Mylan Metformin is metformin, in 500 mg, 850 mg and 1000 mg tablets. It is the first medicine prescribed for type 2 diabetes almost everywhere in the world, and it is also used in polycystic ovary syndrome and prediabetes. “Mylan” is the manufacturer, not a different medicine.
What is Mylan Metformin?
The South African Medicine Price Registry lists Mylan Metformin as Schedule 3 tablets containing metformin hydrochloride at 500 mg, 850 mg and 1000 mg.
Mylan is a generic manufacturer. Metformin is also sold as Glucophage, Glucomet, Bigsens and many others, and being dispensed a different brand from last time is ordinary generic substitution. See also the general metformin guide.
Metformin is a biguanide, and it lowers blood sugar in three ways, none of which involve forcing the pancreas to make more insulin:
- It reduces glucose production by the liver, which is its main action. In type 2 diabetes the liver releases too much glucose, particularly overnight.
- It improves insulin sensitivity, so muscle and fat take up glucose more readily.
- It slightly reduces glucose absorption from the gut.
The consequence that matters clinically: metformin does not cause low blood sugar on its own. It reduces excess glucose production rather than driving insulin release, so used alone it does not push blood sugar below normal. Hypoglycaemia becomes a risk only when metformin is combined with insulin or a sulfonylurea such as gliclazide.
It is also weight-neutral or mildly weight-reducing, unlike several other diabetes medicines that cause weight gain — a meaningful advantage.
Why three strengths. Metformin is built up gradually, typically starting at 500 mg once daily with food and increasing over weeks. This titration is not caution for its own sake — it is how the gut side effects are avoided, and going too fast is the main reason people abandon the medicine.
Modified-release versions exist and are considerably gentler on the stomach. If standard metformin causes intolerable diarrhoea, ask about the MR form before giving up on it — this is a common and easily solved problem.
What is Mylan Metformin commonly used for?
- Type 2 diabetes — the first-line medicine, and usually continued even as others are added.
- Prediabetes, to reduce the chance of progressing to diabetes, particularly in younger people and those with a high BMI.
- Polycystic ovary syndrome (PCOS) — improving insulin resistance, helping restore regular ovulation, and reducing symptoms. A common use in women who do not have diabetes.
- Gestational diabetes, where metformin is used and generally considered safe.
- Preventing weight gain with some antipsychotics, and alongside insulin, reducing the dose needed.
Several things are worth knowing:
It has evidence for outcomes, not just numbers. Metformin reduces cardiovascular events and deaths in type 2 diabetes, not only blood sugar readings. That is a stronger claim than most diabetes medicines can make, and it is why it has stayed first-line for decades despite being cheap and old.
Diabetes treatment is about preventing complications — eye, kidney, nerve and cardiovascular damage — which develop silently. Blood sugar high enough to cause damage often causes no symptoms, which is why treatment continues when you feel well.
Lifestyle change is not the soft option; it is the strongest intervention available. Weight loss, reduced refined carbohydrate, and regular activity improve type 2 diabetes more than any single tablet, and in some people substantial weight loss puts it into remission. Metformin works alongside that, not instead of it.
How Mylan Metformin fits into this medicine category
| Group | Examples | Notes |
|---|---|---|
| Biguanides | Metformin (Mylan Metformin) | First-line; no hypoglycaemia alone; weight-neutral |
| Sulfonylureas | Gliclazide, glimepiride | Drive insulin release; hypoglycaemia and weight gain |
| GLP-1 agonists | Ozempic (semaglutide), liraglutide | Injections; substantial weight loss; cardiovascular benefit |
| SGLT2 inhibitors | Empagliflozin, dapagliflozin | Excrete glucose in urine; heart and kidney benefit |
| DPP-4 inhibitors | Sitagliptin, linagliptin | Well tolerated; modest effect |
| Insulin | Various | When other treatment is insufficient |
See the endocrine and diabetes medicines hub.
What to check before using Mylan Metformin
Kidney function is the central consideration. Metformin is cleared by the kidneys, and if it accumulates it can cause lactic acidosis — rare, but serious. Tell your doctor if you have kidney disease, and expect kidney function to be checked before starting and at least annually afterwards.
Also tell them if you:
- Have liver disease, or drink heavily. Alcohol adds to the lactic acidosis risk.
- Have heart failure, or a recent heart attack.
- Have a severe infection, or are seriously unwell.
- Are due for a scan with contrast dye, or surgery. Metformin is usually stopped temporarily around both — make sure whoever is arranging it knows you take it.
- Take other diabetes medicines, particularly a sulfonylurea or insulin, where hypoglycaemia becomes possible.
- Take diuretics, ACE inhibitors or ARBs, anti-inflammatories, or cimetidine.
- Are pregnant or breastfeeding.
- Have vitamin B12 deficiency, or symptoms of it. Long-term metformin reduces B12 absorption, and this is under-recognised — B12 should be checked periodically, particularly if you develop tingling in the hands or feet, or unexplained tiredness.
Sick day rules matter, and are the single most practical thing on this page. Stop metformin temporarily and contact your doctor if you become dehydrated — vomiting, severe diarrhoea, high fever, or being unable to drink normally. Dehydration reduces kidney clearance, and that is the situation in which lactic acidosis actually happens. Restart once you are eating and drinking normally again.
Practical points:
- Take it with or just after food, which substantially reduces stomach upset.
- Follow the titration. Increase slowly as directed.
- Swallow modified-release tablets whole.
- Keep your blood tests — HbA1c, kidney function, and periodically B12.
- Do not stop because your readings are good. That is the medicine working.
Possible cautions and when to ask a pharmacist or doctor
The commonest effects are diarrhoea, nausea, abdominal discomfort, wind and a metallic taste. These affect a substantial minority, are worst when starting or increasing the dose, and usually settle within a few weeks. Taking it with food, increasing slowly, or switching to the modified-release form solves this for most people.
Get emergency help for:
- Lactic acidosis — deep or rapid breathing, severe weakness, unusual muscle pain, severe nausea and vomiting, abdominal pain, feeling very cold, or a slow or irregular heartbeat. It is rare, but it is a medical emergency and it typically occurs alongside dehydration, kidney impairment, severe illness or heavy alcohol use.
- Swelling of the face, lips or tongue, or difficulty breathing.
Seek prompt advice for:
- Tingling or numbness in hands or feet, or unexplained tiredness — possible B12 deficiency.
- Persistent diarrhoea that is not settling after a few weeks.
- Symptoms of low blood sugar — shaking, sweating, confusion, hunger — particularly if you also take a sulfonylurea or insulin.
- A rash.
- Any illness causing vomiting, diarrhoea or dehydration — apply the sick day rules.
Contact your doctor if your readings stay high, if you cannot tolerate the medicine, if you are planning pregnancy, or if another prescriber starts you on something new. If side effects are making you consider stopping, say so — the modified-release form, a slower increase, or a different medicine are all available, and stopping without a plan is the one option that costs you something.
Related medicine guides
Frequently asked questions
What is Mylan Metformin 500 used for? Type 2 diabetes, and also prediabetes and polycystic ovary syndrome. 500 mg is the usual starting strength, increased gradually.
What is Mylan Metformin 850 used for? The same conditions, at a higher dose reached during the gradual increase.
What is Mylan Metformin 1000 mg used for? The same, at the higher end of the usual range. Which strength you take depends on your response and kidney function.
Is Mylan Metformin different from other metformin? No. Mylan is the manufacturer. The active ingredient is identical to Glucophage and other brands.
Does it cause low blood sugar? Not on its own. It reduces excess glucose production rather than driving insulin release. Hypoglycaemia becomes a risk when combined with insulin or a sulfonylurea.
Why does it upset my stomach? Diarrhoea and nausea are common when starting or increasing. Take it with food, increase slowly, and ask about the modified-release form — that solves it for most people.
Do I need to stop it when I am ill? Yes, temporarily, if you are dehydrated — vomiting, severe diarrhoea, high fever, or unable to drink normally. Contact your doctor and restart when eating and drinking normally.
Does it cause vitamin B12 deficiency? Long-term use reduces B12 absorption. Levels should be checked periodically, particularly if you develop tingling in the hands or feet.
Can I take it in pregnancy? Metformin is used in gestational diabetes and PCOS in pregnancy and is generally considered safe, but discuss it with your doctor.